module.exports.calculate = {
    add:function(a,b){
        if( !isNaN( a ) | !isNaN( b ) )
        {
         return console.log(a+b)
        }else{
            console.log("数据类型错误？")
        }
    },
    del:function(a,b){
        return console.log(a-b)
    },
    cf:function(a,b){
        return  console.log(a*b)
    },
    chf:function(a,b){
        return  console.log(a/b)
    }
}